Inflammatory diseases are by far the most important causes of morbidity and mortality worldwide. While there are effective diagnostic and therapeutic methods for acute inflammatory diseases (predominately caused by pathogens) in many cases, the diagnosis of chronic inflammatory diseases is mostly difficult, and the therapy thereof is limited to symptomatic measures. Non-invasive imaging methods, such as echocardiography, computer tomography and nuclear magnetic resonance spectroscopy, provide detailed anatomic information and are thus valuable tools for evaluating the function of organs. However, with none of the methods mentioned has it been possible to date to detect inflammatory processes unambiguously with high spatial resolution.
In recent years, the use of fluorinated compounds as contrast agents in the detection of inflammatory diseases has gained much attention in the medical field. Although first limited to 18F-labeled compounds such as 18F-labeled glucose, which can be detected via PET (Positron Emission Tomography), the current focus has shifted to 19F-containing compounds which can be detected via magnetic resonance imaging (MRI). As a further advantage, 19F-containing compounds are easier accessible and do not suffer from the drawback of being radioactive.
The detection of inflammatory processes in the (human) body by MRI is based on the phenomenon that fluorinated compounds, such as fluorocarbons, are taken up by monocytes/macrophages in such a way that the cells become specifically labeled. The fluorinated compound, also referred to as a contrast agent, thus accumulates in the inflamed tissue which is usually further comprising an increased concentration of macrophages at the inflamed site. A lot of attention has been focused on the development of suitable contrast agents that show a preference for the infected tissue while being well-tolerated by the patient.